Volker Betz
Existence of Gibbs measures relative to Brownian motion
(48K, Latex 2e)

ABSTRACT.  We prove existence of infinite volume 
Gibbs measures relative to Brownian motion. We require the pair potential $W$ to 
fulfill a uniform integrability condition, but otherwise our restrictions on 
the potentials are relatively weak. In particular, 
our results are applicable to the massless Nelson model. 
We also prove an upper bound for path fluctuations under the infinite volume Gibbs 
measures.